Drop in cosmic radiation reported

Every day, Earth is bombarded by galactic cosmic rays–subatomic particles accelerated to high energies by distant supernovas, stellar flares, and other explosions. On Dec. 21st, ground-based neutron monitors detected a sudden decrease in this cosmic radiation.
What happened? Over a 48-hour period beginning on Dec. 21st, a series of three CMEs swept past Earth, delivering glancing blows to our planet’s magnetosphere. These CMEs swept aside many of the cosmic rays that would normally bombard our planet. The dip in cosmic rays is called a “Forbush Decrease,” named after physicist Scott E. Forbush who first described it in the 20th century.

The ongoing Forbush Decrease is producing some of the lowest radiation levels of the current solar cycle. This is good news for airline passengers, pilots, flight attendants and astronauts, all of whom absorb cosmic rays during their travels.